269 Letter to the Editor
International Braz J Urol
Official Journal of the Brazilian Society of Urology
Vol. 31 (3): 269-269, May - June, 2005
RE: RADIOLOGICAL CLASSIFICATION OF RENAL ANGIOMYOLIPOMAS
BASED ON 127 TUMORS
A. PRANDO
Int Braz J Urol. 2003; 29: 208-16
Dear Editor,
We read the article by Dr. Prando with inter-est (1). He evaluated the radiological findings of 127 angiomyolipomas (AML) and defined 4 categories depending on the fat content of the tumors. The au-thor defined pattern-I as small (< 1.5 cm), intrarenal, homogenous and predominantly fatty lesions and pro-posed that these lesions tend to become more heter-ogenous (with increasing amounts of non-fatty soft tissue, intratumoral vessels or hematoma) if they grow. However, we would like to report a case of a large ruptured renal AML with very high amounts of fatty tissue. She was a 46-year-old woman presented to emergency service because of a sudden occurence of left upper abdominal pain. A plain abdominal film was negative and abdominal ultrasonography showed highly echogenic lesion in the lower pole of left kid-ney surrounded by a hypoechogenic mass. Enhanced computed tomography (CT) of the abdomen
con-Figure 1 – Left renal AML with perinephric hemorrhage (H). Enhanced CT scan shows homogenous mass with dominant fat attenuation (T).
firmed the presence of large perinephric collection with density of blood (+34 HU) including a 9-cm tumoral mass (-85 HU in all regions of the mass) in the center of the hematoma (Figure-1). The patient’s general condition deteriorated in a few hours with fall in hemoglobin levels. An emergency operation was planned and nephrectomy with evacuation of a large amount of blood clots was carried out. Patho-logical examination of the mass revealed AML which had been macroscopically seen as yellow colored fatty tissue in cross-sections. The tumor was demonstrat-ing the histological features belongdemonstrat-ing to pattern-I in Dr. Prando’s categorization system. However, its size was discordant with the same group.
According to our experience, the prevalence of huge AML’s with very high amount of fat is very rare. We think that this kind of categorization sys-tems would help identifying imaging characteristics of AML, their differential diagnosis and further thera-peutic alternatives for most cases as Dr. Prando had already emphasized in the paper. But, larger series of study groups would provide information of unique categorization systems accepted worldwide.
We thank Dr. Prando for this interesting and insightful article.
Respectfully,
